Polyurethanes are versatile, being used by way of example as seat cushioning in the furniture industry and as binders for particleboard, as insulation material in the construction industry, as insulation material by way of example for pipes, hot-water tanks, and refrigerators, and as cladding components, for example in vehicle construction. In particular, polyurethanes are frequently used in automobile construction, for example in the external cladding of automobiles as spoilers, roof elements, and springing elements, and also in the interior cladding of automobiles as roof cladding, carpet-backing foam, door cladding, steering rings, control knobs, and seat cushioning.
In this context it is known that polyurethanes tend to emit organic substances which can cause unpleasant odors or, in the event of high concentration, can cause health-related problems.
Enclosed spaces are in particular affected here, for example in the interiors of buildings or of vehicles such as automobiles. An example of these emissions is emission of aldehydes. Various attempts have already been made to reduce these aldehyde emissions: by way of example, EP 1428847 says that aldehyde emissions can be reduced by adding polymeric substances having primary and/or secondary amino groups.
By way of example EP 1428847 says that aldehyde emissions can be reduced by subsequently adding polymeric substances having primary and/or secondary amino groups. Responsible for the reduction in emissions are the amine groups in the polymer. Since they are isocyanate-reactive and are very largely deactivated by reaction with the isocyanate, the polymeric active ingredient ought to be given to the foam already produced. A disadvantage here is a complex process with an additional step of aftertreatment of the foam. There is no possibility for use in compact systems or closed-cell foams.
US 2006/0141236 describes the use of hydrazine compounds as aldehyde scavengers in polyurethanes. In this case the active substance is introduced directly into the polyol component. Hydrazines and hydrazine derivatives, however, have a catalytic activity and may influence the polyurethane reaction. Moreover, only a low level of reduction in aldehyde emissions is obtained, of around 60%.
US 20130203880 describes the use of polyhydrazodicarbonamide as a substance for reducing aldehyde emissions in polyurethane foams. A significant reduction in aldehydes is achieved, however, only when the amount of polyhydrazodicarbonamide added is large, being from 2 to 5.5% by weight in the polyol component. Since polyhydrazodicarbonamide likewise has catalytic properties, the reaction profile is altered through the addition of this substance in this order of magnitude.